Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. See news and announcements

GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

24896 results found.

  1. BeppoSAX: GRB990625
  2. Late-time HST/STIS Observation of GRB 990123
  3. Optical Observations of GRB 990506
  4. GRB990527 Optical Observations
  5. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  6. Late Afterglows of GRBs 990510, 990123
  7. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  8. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  9. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  10. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  11. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  12. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  13. radio observations of X-ray/GRB transient field
  14. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  15. Optical report on X-ray/GRB transient
  16. radio detection of X-ray/GRB transient
  17. BeppoSAX: A new fast X-ray transient
  18. GRB 990510: optical observations
  19. GRB 990510: optical linear polarization
  20. GRB 990510: optical observations
  21. GRB990510: X-ray afterglow
  22. GRB 990510: Broad Band Break
  23. GRB 990510: BATSE Observations
  24. GRB 990510: BeppoSAX/GRBM observations
  25. GRB990510 optical observations
  26. GRB 990510 optical observations
  27. GRB 990506 Radio Observations
  28. GRB 990123, optical monitoring
  29. GRB 990506: BATSE Observations
  30. GRB 990506, optical observations
  31. GRB 990506, Optical Observations
  32. GRB 990506 optical observations
  33. GRB 990506, optical observations
  34. GRB 990506, armchair astronomy
  35. GRB 990506, optical observations from +1 to +3 hours
  36. GRB 990506, optical observations
  37. GRB990506 observation plan
  38. IPN localization for GRB990506
  39. GRB990323 PRECISE IPN POSITION
  40. GRB 990316 Optical Observations
  41. GRB 990316 optical observations
  42. GRB990316: simultaneous optical observation
  43. GRB990316 - Optical null results
  44. GRB990308 not a new SGR
  45. GRB 990308a and GRB 990308b
  46. GRB990308, Possible new SGR~0209+70
  47. GRB 990123, Field Photometry
  48. GRB 990217 Optical Observations
  49. BATSE Flight Anomaly
  50. GRB990217: BeppoSAX/GRBM data
  51. GRB990123 observations
  52. GRB990217 Optical observation
  53. GRB990123, Optical Observation
  54. GRB 990123: Discovery of the Probable Host Galaxy
  55. GRB 990123: Reduced HST Images
  56. GRB19990123 observations
  57. GRB 990123: BVRI standards in the field
  58. GRB981220, field photometry
  59. GRB990123, Optical observation
  60. GRB990123, 15-GHz limits
  61. GRB 990123: New Constraints on Possible Foreground Galaxies
  62. GRB990123 Optical Observations
  63. GRB990123, Probability of gravitational lensing
  64. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  65. GRB990123, Preliminary Lens Search Results
  66. On the Lensing Interpretation of GRB 990123
  67. Search for Potential Images of GRB 990123
  68. Search for Potential Images of GRB 990123
  69. GRB990123, Optical BVRI Observations
  70. GRB 990123: near-infrared observations.
  71. GRB990123, OSSE observations
  72. GRB990123: NIR Observation
  73. GRB990123, ASCA X-ray observation of afterglow
  74. "GRB 990123: New BV Observations"
  75. GRB 990123 Optical Follow-Up
  76. GRB 990123: BATSE Observations
  77. GRB990123 Optical Observations
  78. GRB 990123: New Optical Observations, Decay Measure
  79. GRB 990123 Optical Follow-Up
  80. GRB 990123: Possible Gravitationally Lensed Burst?
  81. GRB990123, optical observation
  82. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  83. GRB990123, Optical observation
  84. GRB 990123: Optical Decay Slope
  85. GRB 990123 r-band photometry
  86. GRB 990123 Optical Follow-up
  87. GRB990123, early optical counterpart detection
  88. GRB990123 Optical Observation
  89. Possible identification of SN1999E with GRB980910
  90. Optical Observations of GRB 981220
  91. GRB 981226: radio variable
  92. GRB981220
  93. GRB981220, Correction to GCN 179
  94. GRB 981220 Optical observations
  95. GRB 981226 Optical Observations
  96. GRB 981220 and GRB 981226, optical observations
  97. GRB981226 Optical Observations
  98. GRB981226 BeppoSAX follow up
  99. GRB 981226
  100. GRB 981226 optical observations

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov